Table 2. Characteristics of the included studies for survival analysis.

Study	Year	Country	Cancer types	patients	Median age [Range] (years)	Follow-up time	Counting Method	Cut-off value (positive/high)	Survival outcomes	Source of data	NOS score
Aksoy et al. [49]	2017	Turkey	mCRPC	30	——	NR	IHC	A > 50	OS (U), OS (M)	curve+direct	6
Bhattacharya et al. [50]	2019	U.K.	LPC	218	——	85 months (median)	IHC	Median scores	BRFS (U), BRFS (M) DMFS (U)	direct	7
Dayyani et al. [14]	2016	U.S.A.	mADPC	66	72 [57, 93]	1.4–2.6 years	ELISA	ln(OPN) > 11.9	PFS (U), PFS (M)	direct	7
Forootan et al. [32]	2006	U.K.	PA	70	73	0–80 months	IHC	A > 30	OS (U)	curve	6
Hotte et al. [51]	2002	Canada	HRPC	100	73 [50–86]	0–26 months	ELISA	>115 ng/ml	OS (U), OS (M)	curve+direct	8
Ramankulov et al. [52]	2007	Germany	PC	90	——	2.7–88.4 months	ELISA	>1099 μg/l	DSS (U), DSS (M)	direct	8
Vergis et al. [53]	2008	U.K.	LPC	I: 201 II: 285	I: 67 [50, 80] II: 61 [45–78]	——	IHC	A > 0	BRFS (U), BRFS (M)	direct	7

Abbreviations: A, percentage of positive cells; BRFS, biochemical relapse-free survival; DMFS, distant metastasis-free survival; DSS, disease-specific survival; ELISA, enzyme-linked immunosorbent assay; HRPC, hormone-refractory prostate carcinoma; IHC, immunohistochemistry; LPC, localized prostate cancer; M, multivariate analysis; mADPC, metastatic androgen-dependent prostate cancer; mCRPC, metastatic castrate-resistant prostate cancer; OS, overall survival; PA, prostate adenocarcinoma; PC, prostate cancer; PFS, progression-free survival; U, univariate analysis. Cohort I: radiotherapy cohort, Cohort II: radical prostatectomy cohort.